Staten Island Advance/Andrew LisantiEmergency officials tend to two pedestrians struck by an SUV on Slosson Avenue in Castleton Corners.STATEN ISLAND, N.Y. -- Authorities continue to probe Tuesday’s fatal accident in Castleton Corners in which a grandmother walking her grandson to school was killed by an SUV that careened onto the sidewalk after colliding with another vehicle.

“We are investigating the accident alongside the NYPD’s Accident Investigation Squad,” said William J. Smith, spokesman for District Attorney Daniel Donovan.

Smith said he couldn’t disclose details of the probe since it’s pending.

A law enforcement source said one of the two vehicles in the crash — a 2004 Chevy Tahoe and a 2005 Subaru Forester — went through a steady red light before the Tahoe fatally struck Beata Kurpiewski, 59.

However, to bring criminal charges against that driver, at least one other “aggravating” factor, such as speeding or reckless driving, would have had to contribute to the crash.

Mrs. Kurpiewski, of Brooklyn, was hit on the corner of Slosson Avenue at Windsor Road at 11:45 a.m.